| 摘要 |
<p>A Hybrid Fiber-Coax ÄHFCÜ telecommunication system including several modulation devices (MC1-MCn) and a combiner device (CSN) coupled thereto. The modulation devices provide modulated telecommunication signals under the form of output currents that are applied to the combiner device that is further connected to a coaxial cable (COAX) for transmitting thereon these modulated signals in predetermined frequency channels according to the Frequency Division Multiple Access ÄFDMAÜ structure. The invention consists in operating the combiner device as a current-mode summing node instead as of a voltage-mode summing node. As a result, the implementation is relatively easy, because a current summing node may be just a single junction point, and its linearity is thus obviously high. Furthermore, drivers or power amplifiers are generally not required between the modulation devices and the combiner device because there is no power dissipated in this combiner device, thus no power loss to be compensated. Additionally, the integration volume of the HFC telecommunication system is reduced, as well as the cost for an external combiner. The invention is also applicable to quadrature-phase modulation systems. <IMAGE></p> |
